Liquid biopsies in endocrine neoplasia-a systematic review

Abstract

Background: The use of liquid biopsies as a non-invasive method for early recognition and management of cancer is rapidly evolving. Circulating tumor cells (CTCs), cell-free DNA (cfDNA), and circulating tumor DNA (ctDNA) are potential biomarkers for cancer. This review identifies the diagnostic and treatment monitoring value of CTC-, cfDNA-, and ctDNA-based biomarkers in endocrine neoplasia. Methods: A search was performed in Embase and PubMed databases from September to November 2018. The search included liquid biopsies measuring CTC, cfDNA, ctDNA, and endocrine neoplasia terms. Articles within the last 5 years featuring original data in regard to detection of biomarkers from endocrine patient blood samples were retained. Results: The search identified 622 unique references. Of these, 65 articles were selected for inclusion which assessed patients with adrenal, ovarian, pancreatic, testicular, and thyroid tumors, most of which were thyroid. No publications were identified for parathyroid and pituitary neoplasms. Conclusions: There is a large variation in mutation detection and wide estimates of sensitivity and specificity indicating that liquid biopsies are not currently useful as a surrogate for tissue-based biopsy for diagnosis of endocrine neoplasms. Once a tumor is diagnosed and the mutations defined, liquid biopsies may be useful for monitoring the clinical course.